This invention relates to methods and alarm systems for detecting, by density measurement, dangerous stratification of fuel in a fuel tank.
There has been previously proposed a fluid density measuring system for continuously monitoring the density of a fuel in a fuel tank. Such a system comprises a capacitance transducer disposed inside a fuel tank and connected to electronic circuitry which measures the capacitance of the transducer (which is an effective measure of fuel density) and outputs a signal proportional to the fuel density. There is, however, no provision in such a system for comparison of the density of the fuel at several heights within the fuel tank, and dangerous stratification of the fuel can arise without any direct indication being given by the system.